Part of his point is DO will ignore apt-get where kernels are involved. Sure, it'll look like you're running the latest, but unless you undertake additional steps, it'll be booting their kernel, not yours.
If you want to do such low-level things as upgrade kernels, then maybe DO's one-click-and-poof-you're-running is less important to you than some other features and DO isn't the best option for you.